1. Field of the Invention
The present invention relates to an improved self-lifting apparatus and, more particularly, to an improved self-lifting apparatus for box cover and is conveniently assembled, and allows box cover to be lifted automatically and can be used as file clip in the box.
2. Description of the Prior Art
As shown by FIG. 1, the conventional self-lifting apparatus is provided with a heated iron wire on the wrapping edge of its lower end to force both ends of the iron wire outside the box to be inserted into the holes on the box when the box is closed, and thus allows the flexibility of iron wire to lift the box cover as soon as the closed end of the box is opened.
The conventional self-lifting apparatus is useful for the non-complicated boxes, such as cashbox and pencil box, and is, however, inconvenient for the complicated products such as portable safe. Disadvantages are as illustrated as follows:
1. The conventional self-lifting apparatus is assembled in a fixed manner that requires both iron wire and wrapping edge to be installed in the box before the parts are assembled and, therefore, production becomes time-consuming and the apparatus can be broken easily. When installed in the safe made of hard materials, the conventional self-lifting apparatus can be used approximately five thousand times only.
2. The conventional self-lifting apparatus allows box cover to be lifted with its flexibility. To include file holders in the box, holed pieces have to be installed underneath the cover to allow the -shaped bars with outward-bended ends to penetrate through and, therefore, the production requires a few more steps and the costs of materials and labors increase as well.